Field of the Invention
The present invention relates to an image pickup apparatus having a GPS function and an interval photographing function, and a method of controlling the same, and more particularly to a GPS control technique and azimuth measurement used in interval photographing for performing photographing at predetermined intervals.
Description of the Related Art
In an image pickup apparatus having a global positioning system (GPS) function and an interval photographing function of performing photographing at predetermined intervals, in general, positioning by the GPS function and interval photographing are asynchronously set. For example, Japanese Patent Laid-Open Publication No. 2007-295034 discloses a technique for starting the GPS function by detecting that photographing is to be performed outdoors based on a distance to an object and brightness of the object. Further, Japanese Patent Laid-Open Publication No. 2001-257920 describing a camera system including a GPS receiver and an azimuth meter discloses a technique for automatically performing photographing when a spot set beforehand is reached. Here, with reference to FIG. 10, a description will be given of a GPS positioning interval and a photographing interval of interval photographing, and electric current consumption of the image pickup apparatus caused by GPS positioning and interval photographing, in the image pickup apparatus having the GPS function and the interval photographing function.
Reference numerals TG1, TG2, . . . , TG8 in FIG. 10 each denote a timing of positioning performed by the GPS. Reference numerals T11, T12, and T13 in FIG. 10 each denote a photographing timing of interval photographing. Reference numeral 1001 in FIG. 10 denotes an electric current consumption amount detected when GPS positioning is performed at TG1. Similarly, reference numerals 1003 to 1005, 1007 to 1009, and 1011 denote electric current consumption amounts detected when GPS positioning is performed at TG2, TG3, . . . , TG8, respectively. Further, reference numeral 1002 denotes an electric current consumption amount detected when interval photographing is performed at T11, and reference numerals 1006 and 1010 denote electric current consumption amounts detected when interval photographing is performed at T12 and T13, respectively.
As shown in FIG. 10, since the interval of positioning by the GPS and the photographing interval of interval photographing are asynchronously set, for example, results of positioning performed by the GPS are not reflected on photographing. Therefore, there is a problem that electric power is wastefully consumed e.g. at the timings 1003 and 1004 in FIG. 10.
Further, an increase in the difference (ΔT) between the timing (TG1) of positioning performed by the GPS and the timing (TI1) of interval photographing causes a problem that the newest position information is not added to an image.